687228209 has 2 divisors, whose sum is σ = 687228210. Its totient is φ = 687228208.

The previous prime is 687228203. The next prime is 687228229. The reversal of 687228209 is 902822786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 545689600 + 141538609 = 23360^2 + 11897^2 .

It is a cyclic number.

It is not a de Polignac number, because 687228209 - 2¹⁶ = 687162673 is a prime.

It is a super-2 number, since 2×687228209² = 944565222490695362, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 687228209.

It is not a weakly prime, because it can be changed into another prime (687228203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343614104 + 343614105.

It is an arithmetic number, because the mean of its divisors is an integer number (343614105).

Almost surely, 2^687228209 is an apocalyptic number.

It is an amenable number.

687228209 is a deficient number, since it is larger than the sum of its proper divisors (1).

687228209 is an equidigital number, since it uses as much as digits as its factorization.

687228209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 193536, while the sum is 44.

The square root of 687228209 is about 26215.0378409035. The cubic root of 687228209 is about 882.4707634224.

The spelling of 687228209 in words is "six hundred eighty-seven million, two hundred twenty-eight thousand, two hundred nine".